Double-Digit Multiplication Strategies

Have you ever wondered if your students will master double-digit multiplication? There are so many techniques, but which will be the best one for your learners? A few years back, I was struggling with these questions.

When we were in school, we were taught the standard algorithm. I can still remember standing nervously by the chalkboard completing long problems in front of my class. I was never really sure what I was supposed to do next. There were no tricks or shortcuts - just the basics of multiplication. And if the standard algorithm didn't work for you...well, you were up a creek. Thankfully, today, we have more than one way to teach multiplication.

3 "Out of the Box" Methods for Teaching Double-Digit Multiplication

TURTLEHEAD 

We know not every student learns quite the same way. So I ventured onto the web and wandered down the YouTube rabbit hole. However, it wasn’t a complete waste of time. I found one video that stood out from the rest in explaining double-digit multiplication -- the turtlehead method!

This video is very primary, but the kids will connect to the silly graphics and music. This method demonstrates all the important steps that kids usually forget to do in the standard algorithm. The turtle helps them remember where to start multiplying, to cross off the multiplier, and to put in that magic zero! After just one exposure to the video more students were suddenly becoming accurate as they follow the turtle’s cues. To help students remember the steps and give them a visual on the wall, you can create a poster.

LATTICE

For some kids, the steps of the standard algorithm or the turtlehead method are just too much for them.

A decade or so ago the trend in math was lattice multiplication. This technique can help you reach those students who struggle with algorithms that use a standard set-up.

Lattice multiplication creates a grid with double-digit numbers placed on the outside. There are diagonal lines that run through the grid to divide the grid boxes into halves. As each number is multiplied, the values are placed inside the grid. Once all the multiplying is done, the numbers are then added down from the right to left, moving downward.

When using this method, the student doesn’t have to remember about the magic zero. Most mix-ups may happen when students aren’t sure about where to multiply first. In the past, I have shown them how to draw a dot on the top right corner of the box. This will be their starting point for the lattice.

Please note: some standardized testing does not recognize lattice as a legitimate algorithm (or award points for correct answers) because it is not based on place value concepts; it is simply a "cool trick". 

AREA MODEL

One last way to reach students is multiplying using the area model. This organized method uses the concept of area: length x width. The numbers are broken down using expanded notation. Once the numbers are multiplied, the answers go inside the grid created in the area model. All of those answers are then added together to get the final answer.

From experience, I have learned to start with just one technique. As I saw some students struggling, I would introduce a new method to them. Some students were most comfortable with the standard algorithm because that is the technique they were taught by their parents- and that's great! But I would encourage them to at least give these others a try. I would even challenge them to solve using the method most comfortable and them check their answers using a different method.  

At the end of the day the most important thing was a student's ability to correctly solve the problem. And using one method or the next, soon enough, all my students were multiplying with ease!

Need some ideas for LONG DIVISION?
Click the link below to read about three strategies for success!

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